package jdbc;

import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

/**
 * 别名
 */
public class JDBCDemo6 {
    public static void main(String[] args) {
        try (Connection connection = DBUtil.getConnectiom();
        ){
            Statement statement = connection.createStatement();
            String sql = "SELECT COUNT(*) count  " +
                    "FROM class c " +
                    "JOIN student s ON c.id=s.class_id " +
                    "WHERE c.name='1年级1班' ";
            System.out.println(sql);

            ResultSet rs =statement.executeQuery(sql);
            while(rs.next()){
                int count = rs.getInt("count");
                System.out.println("人数："+count);
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
}
